I looked for some topic about this, but couldnt find it, so I'm writing this! If someone has already did that, please, let me know:
Since 'Loader Layouts' does not work in mobile apps, I did some modifications directly in the CSS file after I exported the project to cordova. Is that ok for Scirra? Because I understand the loading screen, with the small blue bar is kind of a mark of C2 apps/games!!
If there is no implications on doing this I can share what I did for everyone.